Haloneopentyl phosphorodiamidate

ABSTRACT

WHEREIN Hal is Cl or Br, X is H, Cl, Br or CH3, Y is O or S and each of R1, R2, R3 and R4 independently is H, CH2OH, CH2OCH3 or CH2OC2H5.   Haloneopentylphosphorodiamidate, useful as a flame retardant for cellulosic materials, of the formula

[451 Jan. 7, 1975 1 HALONEOPENTYL PHOSPHORODIAMIDATE [75] Inventor: Patrick Michael Burke, Wilmington,

Del.

[73] Assignee: E. l. du Pont de Nemours and Company, Wilmington, Del.

22 Filed: June 25, 1973 211 Appl. N0.: 373,146

[52] US. Cl 260/953, 117/136, 260/950, 260/959 [51] Int. Cl. C07f 9/24 [58] Field of Search 260/950, 953, 959, 963

[56] References Cited UNITED STATES PATENTS 2,828,228 3/1958 Glade et a1. 117/136 3,324,205 6/1967 Carpenter et al..... 260/963 3,440,222 4/1969 Walsh et al. 260/953 X 3,688,001 8/1972 Exner et a1. 260/463 FOREIGN PATENTS OR APPLICATIONS 790,663 2/1958 Great Britain Great Britain Japan Primary Examiner-Lorraine A. Weinberger Assistant Examiner-Richard L. Raymond Attorney, Agent, or FirmLouis H. Rombach 1571 ABSTRACT Haloneopentylphbsphorodiamidate, useful as a flame retardant for cellulosic materials, Of the formula wherein Hal is C1 or Br, X is H Cl, Br Or CH Y is O or S and each of R R R and R independently is H, CH O1-l, C1-1 OCH or CH OC H 4 Claims, No Drawings propanol,

HALONEOPENTYL PHOSPHORODIAMIDATE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to haloneopentylphosphorodiamidates which are useful as flame retardants for cellulosic materials.

2. Description of the Prior Art Flame retarding chemicals are known to have many applications in carpets and rugs, materials for building construction, electricaland electronic appliances, apparel, paper and wood products, transportation and home furnishings; Apparel, and especially childrens apparel, has been the basis of much research directed to making it more flame resistant.

Many flame retardants and processes for their application to textilefabrics are known. In the area of cellulosic fabrics, the most commonly used flame retardants are inorganic compounds for example, aluminum sulfate, ammonium phosphate, bromide and sulfamate, antimony chloride, antimony oxides, borax, boric acid and zinc borate. Organic compounds which are used as flame retardants for textile fabrics generally are those organic compounds which contain phosphorus, nitrogen and halogen, either singly or'in combination. Such compounds include dicyandiamide, thiourea, dibromohexabromodiphenyl and tris(2,3- dibromopropyl)phosphate. The above types of flame retardants, although often providing good initial flame retardancy, may not provide durable flame retardancy, the chemical being washed away during laundering; such chemicals need to be applied after each washing. Durable flame retardant finishes for textile fabrics are also known, such as those based on tetrakis(hydroxymethyl)phosphonium chloride or hydroxide and wherein the phosphorus compounds are cured with ammonia on the fabric to form an insoluble fire retardant polymer. Other known durable flame retardant finishes are obtained by coapplying a phosphoric acid derivative with an aminoplast resin which, upon curing, durably fixes the fire retardant chemical on the fabric.

The major problems which often are encountered in the application of flame retardant chemicals to textile materials may include any one or more of the following: (1) unacceptable stiffening of the treated fabric,

that is, unsatisfactory fabric aesthetics; (2) weakening.

of the fiber substrate; (3) unsatisfactory durability to launderings; (4) toxicity, that is, skin sensitization; (5) discoloration of treated fabrics; and (6) high cost.

OBJECTS AND SUMMARY OF THE INVENTION In summary, the invention herein resides in the discovery and use of a compound of the formula wherein Hal is Cl or Br, X is H, Cl, Br 'or CH Y is O or S and each of R, R R and R independently is H, CH OH, CH OCH or CH OC H Preferred compounds herein are of the above formula wherein Hal and X are Br, Y is O and all of the R groups are H or CH OH or two are H and two are CH OH.

DETAILED DESCRIPTION OF THE INVENTION The compounds of the above formula wherein all the R groups are H can be prepared by reacting phosphorus oxychloride (POCI or thiophosphoryl chloride (PSCI with a haloalcohol of the formula HalCH C(CI-I X) CH OI-I, wherein Hal and X are as defined above, to form a phosphorodichloridate, and then with ammonia to form the diamidate. The reactions of POCI and PSCI with compounds containing reactive hydrogens are well known in the art. The aforesaid haloalcohols are well known; many are commercially available. Although polyhaloalcohols containing both chlorine and bromineatoms are useful, be-

cause of their more ready availability polyhaloalcohols l The aforesaid dichloridate which is an intermediate can be isolated and purified, for example, by distillation, but such isolation is not required for the preparation of the compounds of this invention. The condensa v tion of the dichloridate with ammonia to form the inventive diamidate is preferably carried out at low temperatures, for example, 40C to 0C., to minimize the possibledecomposition of the intermediate monoamidate. Moreover, the aforesaid reactions are preferably carried out in the presence of a solvent, such as methylene dichloride, chloroform, carbontetrachloride, toluene or a xylene, the only requirement for the. solvent being that it should be inert to the reactants and the desired product. If desired a catalyst, such as AlCl or AlBr can be used in the initial phosphorus halide reaction but, generally, a catalyst is not required since the reaction proceeds well at normal temperatures and can I be readilycarried to substantial completion by increasing the temperature or by increasing the time of reaction or both. The amination reaction proceeds rapidly without a catalyst. In the initial phosphorus halide reaction the evolved hydrogen chloride can be conveniently removed from the reaction system by passing an inert gas, such as nitrogen, through the system. In the amination reaction the hydrogen chloride can be conveniently removed as formed by adding an acid acceptor, such as triethylamine or pyridine, or by the use of an excess of ammonia.

The hydroxymethyl compounds of this invention, that is, compounds of the invention wherein at least one of R, R, R and R is CH ol-l, can be prepared by reacting the above-described diamidates with formaldehyde. The reaction is preferably carried out in solution under acidic or basic conditions, preferably basic conditions. Since the unsubstituted diamidates, particularly the polyhalo compounds, are not very soluble in water, these compounds are dissolved in a solvent system comprising water and about 25-75% by weight of an organic solvent which is miscible with water, for example, methanol, ethanol, isopropanol, tetrahydrofuran, ethylene glycol, monomethyl ether of ethylene glycol, monoethyl ether of ethylene glycol, polyethylene glycol, acetone, methyl ethyl ketone, dimethylsulfoxide, dimethylformamide or. dimethylacetamide. A convenient form of formaldehyde for use in the methylolation reaction is 37% aqueous formaldehyde. When the reaction is carried out under basic conditions, a convenient pH is 8-12, preferably 9-11. Any soluble alkalizing material can provide the desired basic pl-l, such as sodium silicate, sodium carbonate, trisodium phosphate, sodiumhydroxide or potassium hydroxide; the latter two are preferred. The reaction is carried out at -30C., preferably10-20C. Progress of the methylolation reaction can be conveniently followed byperiodic broad band proton decoupled P-3l nuclear magnetic resonance (NMR) spectrum analysis of the reac- 'tion mixture using 85% phosphoric acid as the external standard. The phosphorodiamidate materials used in the formylation reaction have a characteristic band or multiplet of peaks in the range of.18.'to 22 ppm. relative to the standard. As the'methylol compound is formed, the peaks in the NMR spectrum shift toward the standard and are centered in .the range of 16 to .19 ppm. The number of methylol groups introduced into the phosphorodiamidate molecule will depend upon the molar ratio of formaldehyde to phosphorodiamidate'in the reaction mixture; that is, molar 2,2-bis(chloromethyl )'--chloropropyl-N,N

di(methyoxymethyl)-phosphorodiamidate 2,2-dimethyl-3-bromopropylphosphorodiamidate 2-methyl-2-bromomethyl-3-bromopropylphosphorodiamidate 2,2-bis(bromomethyl)-3-bromopropylphosphorodiamidate 2,2-bis(bromomethy1)-3-bromopropyl-N-- methylolphosphorodiamidate 2,2-bis(bromomethyl)-3-bromopropyl-N,N-dimethylolphosphorodiamidate I 2,2-bis(bromomethyl)-3-bromopropyl-N,N'-dime- 1 thylolphosphorodiamidate 2,2-bis(bromometh-yl)-3-bromopropyl-N,N,N,N'-

tetramethylolphosphorodiamidate 2,2-bis(bromomethyl)-3-bromopropyl-N,NQ

. dimethoxymethylphosphorodiamidate 2,2-bis(bromomethyl)-3-bromopropyl-N ,N,N,N-

t'etramethoxymethylphosphorodiamidate Any suitable method, can be used to incorporate a compound of the invention into the cellulosic material being treated. A convenient method is to apply the compound in solution, thus ensuring good penetration into the cellulosic substrate. Since the compounds of the invention, particularly the'polyhalogenated compounds, have low solubilities in water, a solvent commiscible organic solvent, such as methanol, ethanol,

ratios of about 1:1, 2: 1, 3:1 and 4:1 will provide mono-, I

ditriand tetramethylol derivatives,respectively.

The methoxymethyl and ethoxymethyl compounds of )3 5 the invention can be made by reaction of the appropri-' ate non-methylolated phosphorodiamidate with chloromethyl methyl ether orchloromethyl ethyl ether, respectively, in an alkaline medium, for example, at a pH of 8-12, preferably 9-11, or by etherification of the above-described hydroxymethyl compounds with methanol orethanol, respectively, in an acidic'alcoholic medium, for example, at a pH of 1 5, preferably 2-3.

Typical compounds of the present invention include those vshownin .Table I as well as their thiono analogs. The preferred compounds are 2,2-bis(bromomethyl)-3-bromopropylphosphorodiamidate and its' isopropanol, ethylene glycol, monomethyl ether of ethylene glycol, monoethyl ether of ethylene glycol, polyethylene glycol, tetrahydrofuran, acetone, methyl ethyl ketone, dimethyl'sulfoxide,dimethylformamide or dimethylacetamide, is conveniently used; The preferred water miscible solvents areisopropanol and dimethyl- I formarnide. A sufficient amount of the compositionshould be applied to the cellulosic material to provide the desired amount offflame resistance. The amount of the compound of the invention applied should be 35-10% by weight, based on the weight of fabric, preferably 59%. The solution of the compound'can be applied by spraying or dipping but the preferred method is by a conventional padbath technique. Wet pick-up of solution'is usually 60-200% by weight, based on the weight of fabric, preferably -120%.

The flame resistanc'eimparted to a combustible cellulosic material. by a compoundof this invention, parti'cularly a methylol or alkoxymethyl derivative, is made durable to laundering by fixing or curing the compound after it has been applied to the -substrate. Curing is carried out for a sufficient time and at such a temperature that the compound is insolubilized on the substrate. Representative of such an operation, the substrate which is impregnated with a solution. of a compound of the invention is dried at 20 -115C. Curing is effected at 1-50-190C., preferably 1-60-190C.,in the presence of an acidic curing catalyst for 2-10 minutes, preferably 2-4 minutes. The catalyst is usually dissolved in thesolution of phosphorodiamidate before the solution is applied to the material being treated. The amount of catalyst used is 0.5-5 weight preferably 1-2.5%, based on the weight of the solution. Suitable catalysts are protonic and Lewis acids and include organic acids, such as oxalic, tartaric, glycolic, lactic, succinic, citric and'malic acids and their ammonium salts; salts of inorganic' acids, such as the ammonium salts of hydrochloric, phosphoric and sulfuric acids, zinc fluoroborate,

zinc chloride, zinc nitrate, magnesium chloride and magnesium nitrate; and the hydrochlorides of 2-amino-2-methyl-l-propanol and tris(2-hydroxyethyl- )amine. The preferred catalysts include ammonium chloride and 2-amino-2-methyl-l-propanol hydrochloride.

When the compounds of this invention are used to impart a significant degree of flame resistance to combustible cellulosic materials, they usually are applied as a liquid composition in combination with other agents conventional in the art for enhancing flame resistance and for improving the durability of the effect. The liquid composition generally comprises the phosphorodiamidate, a curing catalyst, a conventional aminoplast resin precursor, described below, and a volatile carrier solvent which can wet, penetrateand swell the cellulose and which is readily removable by volatilization at fixation temperatures. Other adjuvants, such as nonionic wetting agents, may also be advantageously incorporated into the treating solution. The liquid composition generally contains 1.5-20% by weight, preferably 3-15%, of the phosphorodiamidate of the invention in combination with an aminoplast resin precursor, the weight of the aminoplast resin precursor being 50-150% of the weight of the phosphorodiamidate, preferably 75-140%.

Aminoplast resin precursors (that is, resin intermediates) useful herein are water soluble polymethylol compounds containing at least 2 moles of condensed formaldehyde, for example, as N-hydroxymethyl groups of C alkyl ethers thereof. Typical of these aminoplast resin intermediates arethe partial or complete'ethers of polymethylol derivatives of amides, such as urea, thiourea, guanidine and dicyandiamide. Particular examples of such precursors include dimethylolurea, tetramethylolurea, di(methoxymethyl)-urea, dimethylol guanidine, trimethylol guanidine and dimethyloldicyandiamide. Derivatives of substituted ureas can also be used, such as formaldehyde condensates, and their ethers, of ethyleneurea, v methyleneurea, acetylenediurea, diurea, oxydimethyleneurea (uron) and iminodimethyleneurea (triazone). Particular examples of such condensates include dimethylolethyleneurea, i dimethylolmethyleneurea, tetramethylolacetylenediurea, trimethyloldiurea, di(methoxymethyl)uronand di(methoxymethyl)triazone. Derivatives of triazines, such as derivatives of melamine, diaminotriazine, formoguanamine and 2-chloro-4,6- diaminotriazine, can also be used. These represent a preferred class of aminoplast resin intermediates or precursors. Specific examples include formaldehyde adducts such as diand trimethylolmelamine, optionally partially methylated, hexamethoxymelamine, tetramethyloldiaminotriazine and tetramethylol-2- chloro-4,6-diarninotriazine.

If desired the methylol compounds of the invention can be prepared in situ for application to cellulosic substrates. For example, a solution of an invention compound of the above formula wherein all the R groups are H can be mixed in isopropanol with the requisite amount of formaldehyde (as a 37% aqueous solution), the pH of the mixture being adjusted to -11 using aqueous sodium hydroxide. The amount of formaldehyde used will depend upon whether the mono-, di-, tri or tetramethylol compound is desired. The above mixture is then stirred at room temperature for 1-2 hours, readjusting the pH to 10-1 1 if necessary. Resin precursor is then added, if desired, the concentration of the compound is adjusted to the desired level and the pH is adjusted to 7-8. Finally, the acid catalyst is added and the resulting solution is used as a padding bath to treat the cellulosic material which is to be made flame resistant.

Cellulosic fabrics which are treated with a compound of this invention have fabric characteristics, for example, hand, softness and drape, substantially indistinguishable from the untreated fabrics and the imparted flame resistance is durable to laundering. Moreover, since in the compounds of the invention the halogen atom (or atoms) is attached to a carbon atom which is adjacent to a carbon atom which does not contain any hydrogen atom, that is, each carbon atom containing a halogen atom is a to a fully substituted carbon atom, the compounds of the invention exhibit good thermal and photolytic stability because there can be no a,B-elimination of hydrogen halide. Elimination of hydrogen halide may lead to discoloration of the fabric and formation of a corrosive atmosphere. The unusual and unexpected effectiveness of the compounds of the invention as durable flame retardants for cellulosic materials appears to relate to the presence of both halogen and phosphorodiamidate moieties in the compounds.

The compounds of this invention are particularly effective onall forms of cellulose which swell and become flexible upon exposure to the carrier solvent (water or'an organic solvent as described above) used to prepare the solution or liquid composition. Whencomplete penetration of the cellulosic material is achieved, the flame resistance is imparted throughout the material. Suitable cellulosic materials include natural fibers, purified wood pulp and rayon. In the textile field, natural fibers include the preferred fiber cotton, linen, viscose rayon, cuprammonium rayon, jute, hemp and ramie. Such materials can be treated in the form of raw fiber, carded stock, rovings, thread, yarn and felts as well as in the form of knitted and woven fabrics. Cellulosic materials which have been treated with the compounds of this invention are especially useful for tents, stage scenery, upholstery fabrics, slipcovers, draperies, wearing apparel for personnel in close relation to tire or heat, bedding, nightclothes, tarpaulins, insulation, padding, rope, string and twine.

The following experiments demonstrate the utility of the compounds of this invention in combination with trimethylolmelamine as flame retardants for cellulosic materials. The experiments included use of the Vertical Flame Test and determination of Limiting Oxygen index.

Limiting Oxygen Index (LOI) is determined with a 5 X 2 inch piece of fabric spread lengthwise in a vertical plane and supported along its vertical edges. The. spread fabric is positioned inside a transparent cylindrical column open only at the top. The top of the column is l or more inches above the spread fabric. The interior of the column is provided with an upward flow, from its base, of a gaseous mixture of pure oxygen and pure nitrogen. The volume flow rate of each gas making up the mixture is intrumented and manually adjustable. To test fabric in this apparatus, the spread fabric is ignited from the top while gas mixture flows up the column. The flow rates of the nitrogen and oxygen are adjusted until the flame on the ignited fabric just goes out. The ratio of the volume flow of oxygen to the sum of the volume flows of oxygen and nitrogen is then calculated. This value, called the Limiting Oxygen Index,

1 0.002 and is completely burned up in the vertical flame test. Any treated cotton having an LOI value of greater than 0.180 is considered to exhibit some flame resistance. vAir contains. about 21 mole of oxygen; therefore, fabrics with LOI values below about 0.210 can be expected to burn freely in a candle-like manner (from the top to the bottom) in air.

The VerticalFlame Test and char length determination are carried out in a 12 X 12 inch cabinet which is 30 inches high (30.5 cm. X 30.5 cm. X 76.2 cm.) and has a glass front. Gas circulation is provided by a 4 inch (10.2 cm.) high opening beneath the glass front and a 6 inch (15.2 cm.) diameter baffled hole at the top of the cabinet. It is provided with holder brackets on which a specimen holder is hung. The specimen holder sample burning the entire length. If any one sample burns the entire length (BEL), all samples are so rated.

In the following experiments parts shown are by weight unless otherwise indicated. Laundering, also ex- 5 pressed as home washing (HW), was carried out by exposing the fabric to a standard laundering cycle employing a washing solution of 100 g. of a commercial detergent (Tide) per gallons of water and tumble drying the washed fabric.

EXPERIMENTI l 5 Six padbaths were prepared of the following compositions, the catalyst being provides a 2 inch (5.1 cm.) wide by 14 inch (35.6 cm.) high vertical open space and vertical side clips to hold edges of fabric which span this open space. Samples are ignited by a 6 inch (15.2 cm.) high Bunsen burner having a 0.375 inch (0.95 cm.) inside diameter tube and water a luminous flame 1.5 inches (3.8 cm.) long. To conduct 25.

the test, a 2.75 inch X 10 inch (7.0 X 25.4 cm.) fabric sample is held in the specimen'holder by its vertical edges and the specimen holder is hung centrally by the holder brackets. The igniting flame is applied so that 0.75 inch (1.9 cm.) of the lower end of the fabric is in 1 the flame. This exposure is continued for 3.0 seconds andthe' flame is removed. After the fla'me has extinguished itself, the sample is removed from the holder. A hook with an attached weight is inserted into the Cotton twill strips 5 inches X 10 inches (12.7 cm. x 25.4 cm.) were padded in each of the above solutions to a wet pick-up of about 87%,based onthe weight of fabric. The fabrics were dried at C. for 10 minutes and cured at C. for 4 minutes. The treated fabric hand was about the same as that of the untreated fabric. LOI determinations, Vertical Flame Tests and elemental analyses were carried outinitially, after one 3 5 home wash and after 20 home washings. The results are sample on one side of the charred area 0.25 inch (0.6 summarized in Table II.

' TABLE 11 Pad Bath No. 1 1 2- 3 4 5 6 initial Add-On 7 Compound of Ex. 1 3.9 5.2 7.5 7.3 9.2 8.9 Trimethylolmelamine 7.0 7.0 7.0 3.5 7.0 0

% Bromine Initial 2.12 3.05 3.92 4.13 4.68 4117 After 1 HW 0.98 After 20 HW 1.89 2.71 3.40 2.53 3.84 0.78 Retained after 20 1-1w 89 89 87 61 82 16 L01 Initial 0.219 0.242 0.254 0.238 0.261 0.237 After 1 HW 0.224 0.243 0.262 0.221 0.270 0.173 After 20 HW 0.223 0.241 0.256 0.216 0.286 0.174 v Char Length (inches) Initial 7.5 2.5 1.2 3.9 1.4 3.3 After 1 Hw 8.3 2.8 1.6 7.4 0.8 BEL After 201-1w 9.1 2.9 1.5 9.0 0.5 BEL cm.) from the outside edge and 0.25 inch (0.6 cm.) from the lower edge. For 2.0 to 6.0 oz. per square yard- (74-222 g./m. fabric a 0.50 pound (0.227- kg.) weight is used. The corner of the cloth at the opposite edge of the char from the load is gently raised until the sample and weight are clear of supporting surface. The length 65 of the tear which occurs is measured (in inches) and reported as char.length. The char lengths reported below are the averages of 2 or 4 determinations with no The control sample-of fabric burned the entire length. The use of Pad Bath No. 1 containing a compound of this invention provided a significant improvement (before washing) over the control. The use of a compound of this invention without trimethylolmelamine (Pad Bath No. 6) provided a marked improvement (before washing) over the control; however, the treated fabric lacked durability, that is, the flame resistant characteristic was not permanent. In addition to char length, the

bromine content after washing also provides an-indication of the durability of treatment. 1

EXPERIMENT 2 A padbath solution was prepared so as to contain the compound of Example 2 (11.6 g.), dimethylformamide (18.9 g.), trimethylolmelamine (8 g.), 2-amino-2- methyl-l-propanol hydrochloride (2 g.) and water (59.5 g.). Three strips of 5 inch X inch (12.7 cm. X 25.4 cm.) 8 02. cotton twill fabric were padded to a wet pick-up of 87%, based on weight of fabric. The fabrics were dried at 100C. for 10 minutes and cured at 165C. for 4 minutes. The treated fabric hand was about the same as that of the untreated fabric. LOI determinations, Vertical Flame Tests and elemental analyses for phosphorus, bromine and nitrogen were carried out initially, after 1 home wash and after 20 home washes. The results are summarized in Table 111.

TABLE III Initial Add-on Compound of Example 2 9.0

Trimethylolmelamine 7.0

75 Bromine Initial 3.94

After 1 HW 3.34 After 20 HW 3.36

% Phosphorus Initial 0.44

After 1 HW 0.50

After 20 HW 0.40

"/1. Nitrogen Initial 3.18

After l HW 3.11

After 20 HW 3.06

Initial 0.242

After 1 HW 0.253

After 20 HW 0.253

Char Length (inches) Initial 1.7

After 1 HW 0.7

After 20 HW 3.1

As shown by the above, the compound of Example 2 in combination with trimethylolmelamine provides both effective and durable flame retardancy on cotton twill.

In the following examples, parts are parts by weight except where otherwise stated. Broad band proton decoupled P-31 NMR spectra are reported in ppm. relative to 85% phosphoric acid in the manner previously described.

EXAMPLE 1 A mixture of tribromoneopentyl alcohol (162.5 g.; 0.5 mole), phosphorus oxychloride (335 g.; 2.18 moles) and potassium chloride (2.5 g.) was heated to reflux (1 10C.) for 2.5 hours. The excess POCI was removed by vacuum stripping, initially at 110C. and 60 mm. pressure and then at 103C. and 0.9 mm. pressure. The product, a viscous yellow liquid (217 g.), was con- 8 with area ratios 2.03:6.0.

Ammonia (35 g.; 2.06 moles) was added slowly at 10C. to -15C. to a solution of 2,2- bis(bromomethyl)-3-bromopropylphosphorodichloridate (221 g.;'0.5 mole), prepared as'described above,

in 1.000 ml. of carbon tetrachloride. The ammonia addition was continued until the mixture was strongly alkaline, about 4 hours. The solids were isolated by filtration; the ammonium chloride was removed by slurrying the solids with water until the filtrate was free of chloride ion. The recovered product 2,2- bis(bromomethyl)-3-b'romopropylphosphorodiamidate (96.5 g.) exhibited a m.p. of l38-146C. (144-148C.

after recrystallization from isopropanol). Calcd. for

C H O N PBr C, 14.9; H, 2.9; N, 6.95; P, 7.6; Br, 59.6%. Found: C, 15.8; H, 3.8; N, 7.3; P, 7.8; Br,

61.3%. The P-3l (singlet at -17.6 ppm.) and the pro ton NMR spectra exhibited by the product were consistent with the expected structure.

EXAMPLE 2 2,2-Bis(bromomethyl)-3-bromopropylphosphorodiamidate (10.1 g.; 0.025 mole), prepared as in Example 1, was'dissolved in a mixture of dimethylform 4 amide (20 ml.) and water (20 ml.). To the solution at room temperature were added 4.2 g. (0.05 mole) of formaldehyde (37% aqueous solution) and the pH was adjusted to 10.0 with 20% aqueous sodium hydroxide. After standing 'for 1 hour the pH was adjusted to 6.5 with 10% aqueous .hydrochloric acid. The desired product 2,2-bis(bromomethyl)-3-bromopropyl-bis- (hydroxymethyl)phosphorodiamidate was obtained by removing the solvent at 50-65C. at 10-20 mm. pressure. The structure was confirmed by P-31 and proton NMR spectra. In using the compound of this example, if desired, it can be applied to the cellulosic material being treated without isolating it from the solvent in which it is prepared.

I claim:

1 1. Compound of the formula wherein Hal is C1 or Br, X is H, Cl, Br or CH Y is O or S and each of R, R R and R independently is H, CHQOH, 01' CHzOCgHs.

2. The compound of claim 1 wherein Hal and X are Br, Y is O and all of the R groups are H.

3. The compound of claim 1 wherein Hal and X are Br, Y is O, R and R are H and R and R are CH OH.

4. The compound of claim 1 wherein Hal and X are Br, Y is O and all of the R groups are CH OH. 

1. COMPOUND OF THE FORMULA
 2. The compound of claim 1 wherein Hal and X are Br, Y is O and all of the R groups are H.
 3. The compound of claim 1 wherein Hal and X are Br, Y is O, R1 and R2 are H and R3 and R4 are CH2OH.
 4. The compound of claim 1 wherein Hal and X are Br, Y is O and all of the R groups are CH2OH. 